Biosynthesis Of Nanoparticles Research Articles

Argyreia nervosa-driven biosynthesis of Cu-Ag bimetallic nanoparticles from plant leaves extract unveils enhanced antibacterial properties.

Our study specifically explores the biosynthesis of copper-silver bimetallic nanoparticles (Cu-Ag BMNPs) using Argyreia nervosa (AN) plant leaf green extract as a versatile agent for capping, reducing, and stabilizing. This biosynthesis method is characterized by its simplicity and cost-effectiveness, utilizing silver nitrate (AgNO3) and cupric oxide (CuO) as precursor materials. Our comprehensive characterization of the Cu-Ag BMNPs, employing techniques such as X-ray diffraction (XRD), UV-Vis spectrometry, scanning electron microscopy (SEM), Zetasizer, and Fourier transformed infrared spectrometry (FTIR). FTIR analysis reveals biofunctional groups and chemical bands, while SEM and XRD analyses provide morphological and structural details. To evaluate the antimicrobial properties of the Cu-Ag BMNPs, we conducted disc diffusion and minimum inhibitory concentration (MIC) assays against Escherichia coli (E. coli), with results compared to the standard gentamicin antibiotic. It is observed that the 2% and 5% CuO concentrations of AN Cu-Ag BMNPs exhibit substantial antibacterial activity in comparison to AN extract when tested on EPEC. Among these, the Cu-Ag BMNPs at a 2% concentration demonstrate higher antibacterial activity, potentially attributed to the enhanced dispersion of BMNPs facilitated by the lower CuO doping concentration. These two assays showcased the improved antimicrobial activity of Cu-Ag BMNPs, highlighting their synergistic effect, characterized by high MIC values and a broad zone of inhibition in the disc diffusion tests against E. coli. These results emphasize the significant antibacterial potential of the synthesized BMNPs, with a medicinal plant AN leaf extract playing a pivotal role in enhancing antibacterial activity.

Biosynthesis, antibacterial and antifungal activities of Ag nanoparticles prepared using Piper nigrum fruit extract

Biosynthesis, antibacterial and antifungal activities of Ag nanoparticles prepared using <i>Piper nigrum</i> fruit extract

Silver nanoparticles biosynthesis using mixture of Lactobacillus sp. and Bacillus sp. growth and their antibacterial activity

The biosynthesis of nanoparticles offers numerous advantages, including ease of production, cost-effectiveness, and environmental friendliness. In our research, we focused on the bioformation of silver nanoparticles (AgNPs) using a combination of Lactobacillus sp. and Bacillus sp. growth. These AgNPs were then evaluated for their biological activities against multidrug-resistant bacteria. Our study involved the isolation of Bacillus sp. from soil samples and Lactobacillus sp. from raw milk in Dhamar Governorate, Yemen. The synthesized AgNPs were characterized using various techniques such as UV–visible spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The antibacterial properties of the AgNPs were assessed using the modified Kirby Bauer disk diffusion method against multidrug-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa. Our results demonstrated that the use of a bacterial mixture for biosynthesis led to faster and more effective production of AgNPs compared to using a single bacterium. The UV–visible spectra showed characteristic peaks indicative of silver nanoparticles, while XRD analysis confirmed the crystalline nature of the synthesized particles. FTIR results suggested the presence of capping proteins that contribute to the synthesis and stability of AgNPs. Furthermore, TEM images revealed the size and morphology of the AgNPs, which exhibited spherical shapes with sizes ranging from 4.65 to 22.8 nm. Notably, the antibacterial activity of the AgNPs was found to be more pronounced against Staphylococcus aureus than Pseudomonas aeruginosa, indicating the potential of these nanoparticles as effective antimicrobial agents. Overall, our study highlights the promising antibacterial properties of AgNPs synthesized by a mixture of Lactobacillus sp. and Bacillus sp. growth. Further research is warranted to explore the potential of utilizing different bacterial combinations for enhanced nanoparticle synthesis.

Synthesized Gold Nanoparticles with Moringa Oleifera leaf Extract Induce Mitotic Arrest (G2/M phase) and Apoptosis in Dalton's Lymphoma Cells.

The therapeutic potential of chemically synthesized AuNPs has been demonstrated in various types of cancer. However, gold nanoparticles (AuNPs) synthesized using typical chemical methods have concerns regarding their environmental safety and adverse impact on human well-being. To overcome this issue, we used an environmentally friendly approach in which gold nanoparticles were synthesized using Moringa oleifera leaf extract (MLE). The present research was mainly focused on the biosynthesis and characterization of gold nanoparticles (AuNPs) using Moringa oleifera leaf extract (MLE-AuNPs) and explore its anticancer potential against Dalton's Lymphoma (DL) cells. Characterization of the MLE-AuNPs was conducted using UV-Vis Spectroscopy to confirm the reduction process, FTIR analysis to ascertain the presence of functional groups, and XRD analysis to confirm the crystallinity. SEM and TEM images were used to examine size and morphology. After characterization, MLE-AuNPs were evaluated for their cytotoxic effects on Dalton's lymphoma cells, and the results showed an IC50 value of 75 ± 2.31 µg/mL; however, there was no discernible cytotoxicity towards normal murine thymocytes. Furthermore, flow cytometric analysis revealed G2/M phase cell cycle arrest mediated by the downregulation of cyclin B1 and Cdc2 and upregulation of p21. Additionally, apoptosis induction was evidenced by Annexin V Staining, accompanied by modulation of apoptosis-related genes including decreased Bcl-2 expression and increased expression of Bax, Cyt-c, and Caspase-3 at both the mRNA and protein levels. Collectively, our findings underscore the promising anti-cancer properties of MLE-AuNPs, advocating their potential as a novel therapeutic avenue for Dalton's lymphoma.

Biofabrication of Silver Nanoparticles Using Green Seaweed: Characterisation and Antibacterial Evaluation

This study investigates the Chaetomorpha antennina (CA) seaweed-mediated biosynthesis of silver nanoparticles (AgNPs). The synthesis process of silver nanoparticles was monitored over time with the help of an Ultraviolet-visible spectrophotometer and further characterisation studies were also performed. Differential Light Scattering (DLS) measurements revealed a mean particle size of approximately 103.5nm and a mean zeta potential value of -57.5mV for AgNPs. The spherical shape and size of the AgNPs were confirmed through High-Resolution Transmission Electron Microscopy (HR-TEM) imaging, while Energy Dispersive X-ray Spectroscopy (EDAX) analysis provided insights into the elemental composition. The concentration of AgNPs was estimated using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The antibacterial potential of AgNPs was evaluated against both gram-positive (Bacillus cereus, Staphylococcus aureus and Bacillus subtilis) and gram-negative bacterial strains (Klebsiella pneumoniae, Escherichia coli, Shigella dysentriae, Salmonella typhi, Pseudomonas aeruginosa and Proteus mirabilis) using the agar well diffusion method. From the results, AgNPs exhibited significant antibacterial activity against B. subtilis and S. typhi among all the tested concentration levels (25, 50, 75 and 100μl).

Moringa oleifera Seed Cake: A Review on the Current Status of Green Nanoparticle Synthesis

Growing demands for sustainable and ecological nanoparticle synthesis methods have incentivized the scientific community to develop new approaches to counteract these challenges. Green synthesis resorts to biocomponents obtained from plants, bacteria, fungi, and other organisms to synthesize nanostructures, with beneficial gains in the economic and ecological cost associated with the process, simplicity of the process, and resource efficiency. Moringa oleifera, a native plant originally from India with immense nutritive value, has long been used by researchers in the biosynthesis of nanoparticles. Leaves, flowers, bark, and seeds are among the “miracle tree” parts that can be used in nanoparticle green synthesis. Moringa oleifera seed cake, a by-product obtained from defatted seeds, is often overlooked due to its apparent low commercial value. The main objective of this review is to highlight the recent findings reported in the literature on nanoparticles/nanocomposites synthesized with seed cake biocompounds acting as reducing/capping agents. Furthermore, we analyzed the methods currently employed for the extraction of bioactive compounds. Moringa oleifera seed for industrial applications was also addressed.

Gold Nanoparticles Biosynthesis Through Green Synthesis Mediated by Leaf Extract from Diospyros Kaki L. (Persimmon) Using the Microwave Extraction Method

Gold Nanoparticles Biosynthesis Through Green Synthesis Mediated by Leaf Extract from Diospyros Kaki L. (Persimmon) Using the Microwave Extraction Method

Phytosynthesis of silver nanoparticles using aqueous sandalwood (Santalum album L.) leaf extract: Divergent effects of SW-AgNPs on proliferating plant and cancer cells.

The biogenic approach for the synthesis of metal nanoparticles provides an efficient eco-friendly alternative to chemical synthesis. This study presents a novel route for the biosynthesis of silver nanoparticles using aqueous sandalwood (SW) leaf extract as a source of reducing and capping agents under mild, room temperature synthesis conditions. The bioreduction of Ag+ to Ago nanoparticles (SW-AgNPs) was accompanied by the appearance of brown color, with surface plasmon resonance peak at 340-360 nm. SEM, TEM and AFM imaging confirm SW-AgNP's spherical shape with size range of 10-32 nm. DLS indicates a hydrodynamic size of 49.53 nm with predominant negative Zeta potential, which can contribute to the stability of the nanoparticles. FTIR analysis indicates involvement of sandalwood leaf derived polyphenols, proteins and lipids in the reduction and capping of SW-AgNPs. XRD determines the face-centered-cubic crystalline structure of SW-AgNPs, which is a key factor affecting biological functions of nanoparticles. This study is novel in using cell culture methodologies to evaluate effects of SW-AgNPs on proliferating cells originating from plants and human cancer. Exposure of groundnut calli cells to SW-AgNPs, resulted in enhanced proliferation leading to over 70% higher calli biomass over control, enhanced defense enzyme activities, and secretion of metabolites implicated in biotic stress resistance (Crotonyl isothiocyanate, Butyrolactone, 2-Hydroxy-gamma-butyrolactone, Maltol) and plant cell proliferation (dl-Threitol). MTT and NRU were performed to determine the cytotoxicity of nanoparticles on human cervical cancer cells. SW-AgNPs specifically inhibited cervical cell lines SiHa (IC50-2.65 ppm) and CaSki (IC50-9.49 ppm), indicating potential use in cancer treatment. The opposing effect of SW-AgNPs on cell proliferation of plant calli (enhanced cell proliferation) and human cancer cell lines (inhibition) are both beneficial and point to potential safe application of SW-AgNPs in plant cell culture, agriculture and in cancer treatment.

Biosynthesis and screening of cobalt nanoparticles using citrus species for antimicrobial activity

Abstract The synthesis of the nanomaterial is crucial for its characteristics, as well as physiological features. Green nanoparticle production, which reduces metal ions using natural extracts rather than industrial chemical agents, has been created to lower costs, minimize pollution, and improve environmental and human health safety. An aqueous and methanolic extract of a combination of Citrus sinensis and Citrus limetta peel was utilized for the green synthesis of cobalt nanoparticles. UV–Visible, Fourier-transform Infrared, X-ray diffraction (XRD), scanning of electron microscopy (SEM) and other techniques were employed to describe the prepared cobalt nanoparticles. The crystal structure of cobalt nanoparticles was revealed by XRD study. The SEM images of the cobalt nanoparticles revealed the usual subdivision dimensions of 20–30 nm. Using the well diffusion method, the antibacterial activity of the crude extract derived from the combination of the two plants mentioned above and the biosynthesized cobalt nanoparticles was assessed. The result showed that the crude extract and cobalt nanoparticles exhibited antibacterial activity and cobalt nanoparticles exhibited much higher activity than the crude extract. Overall, these findings revealed that formulated cobalt nanoparticle treatment considerably prevented the development of different micro-organisms.

Green synthesis of Superparamagnetic Iron Oxide and Silver Nanoparticles in Satureja hortensis Leave Extract: Evaluation of Antifungal Effects on Botryosphaeriaceae Species.

In recent years, green synthesis methods of metallic nanoparticles (MNPs) have been attractive because of the more facile, cheaper, and appropriate features associated with biomolecules in MNPs biosynthesis. This research represented an easy, fast, and environmentally friendly method to biosynthesis of superparamagnetic iron oxide nanoparticles (SPIONPs) and silver nanoparticles (AgNPs) by the Satureja hortensis leaf extract as stabilizer and reducer. The SPIONPs synthesized in co-precipitation method. The biosynthesized SPIONPs and AgNPs were studied their antifungal effects against three Botryosphaeriaceae plant pathogens, Botryosphaeria dothidea, Diplodia seriata, and Neofusicoccum parvum. UV-visible spectra (UV-Vis), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (Fe-SEM), energy-dispersive X-ray spectroscopy (EDX), and vibrating-sample magnetometer (VSM) analyses were used to evaluate the physicochemical properties and verify the formation of green synthesized SPIONPs and AgNPs. UV-Vis spectra revealed absorption peaks at 243 and 448 nm for SPIONs and 436 nm for AgNPs, respectively. Microscopic and XRD analysis showed that SPIONPs and AgNPs was found spherical in shape with an average particle size of SPIONPs and AgNPs 10 and 12 nm, respectively. The antifungal test against Botryosphaeriaceae species showed that SPIONPs and AgNPs possessantifungal properties against B. dothidea, D. seriata, and N. parvum. However, AgNPs exhibits greaterantifungal activity than SPIONPs. Theresultsof thecytotoxicitytests of SPIONs and AgNPs on the MCF-7 cell line showed that AgNPs was significantly more cytotoxictowardsthe MCF-7 cell line, whereas nosignificant cytotoxiceffect was recorded by SPIONs. Therefore, these biosynthesized MNPs could be substituted for toxic fungicides that are extensively applied in agriculture and contribute to environmental health and food safety.

Synthesis of Ag and AgCl Nanoparticles Using Klasea latifolia and Klassa leptoclada Extracts and Assessment of the Antimicrobial Properties of the Synthesized Nanoparticles and Antioxidant Properties of the Extracts

Background: In green synthesis, metal ions are transformed into nanoparticles through a simple reaction, without the need for surfactants, specific conditions, and other stabilizing agents. Methods: This study performed the biosynthesis of silver nanoparticles using the extract of Klasea latifolia and Klasea leptoclada. objective: In green synthesis, metal ions are transformed into nanoparticles through a simple reaction, without the need for surfactants, specific conditions (e.g., temperature and pressure), and other stabilizing agents. Herbs, including flavonoids and other water-soluble active metabolites, could also be used to reduce metal ions to nanoparticles at room temperature. Therefore, the objective of the current research was to investigate the green synthesis of silver nanoparticles using Klasea leptoclada and Klasea latifolia extracts. Results: Nanoparticles were characterized using the SEM, XRD, UV-Visible Spectroscopy, and EDS methods. The antibacterial properties of the extracts and synthesized nanoparticles were evaluated against Staphylococcus aureus, Bacillus cereus, and Escherichia coli using the agar disk-diffusion and well-diffusion. The antioxidants of the herbs were investigated using the DPPH and FRAP methods, and the IC50 of the extracts was determined as well. The results showed that, although no chlorinated compounds were added to the reaction medium, in addition to silver nanoparticles, silver chloride nanoparticles were also synthesized. The synthesized nanoparticles were spherical (size: 27-38 nm) and had uniform size distribution. Furthermore, the synthesized nanoparticles and extracts exhibited significant antibacterial activity. Conclusion: Many plants have been used for the biosynthesis of silver nanoparticles, but the advantage of using the extract of K.latifolia and K. leptoclada was that in addition to synthesizing silver nanoparticles, silver chloride nanoparticles were also synthesized.

Suppression of Root Rot Fungal Diseases in Common Beans (Phaseolus vulgaris L.) through the Application of Biologically Synthesized Silver Nanoparticles.

The biosynthesis of silver nanoparticles (AgNPs) using plant extracts has become a safe replacement for conventional chemical synthesis methods to fight plant pathogens. In this study, the antifungal activity of biosynthesized AgNPs was evaluated both in vitro and under greenhouse conditions against root rot fungi of common beans (Phaseolus vulgaris L.), including Macrophomina phaseolina, Pythium graminicola, Rhizoctonia solani, and Sclerotium rolfsii. Among the eleven biosynthesized AgNPs, those synthesized using Alhagi graecorum plant extract displayed the highest efficacy in suppressing those fungi. The findings showed that using AgNPs made with A. graecorum at a concentration of 100 μg/mL greatly slowed down the growth of mycelium for R. solani, P. graminicola, S. rolfsii, and M. phaseolina by 92.60%, 94.44%, 75.93%, and 79.63%, respectively. Additionally, the minimum inhibitory concentration (75 μg/mL) of AgNPs synthesized by A. graecorum was very effective against all of these fungi, lowering the pre-emergence damping-off, post-emergence damping-off, and disease percent and severity in vitro and greenhouse conditions. Additionally, the treatment with AgNPs led to increased root length, shoot length, fresh weight, dry weight, and vigor index of bean seedlings compared to the control group. The synthesis of nanoparticles using A. graecorum was confirmed using various physicochemical techniques, including UV spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) analysis. Collectively, the findings of this study highlight the potential of AgNPs as an effective and environmentally sustainable approach for controlling root rot fungi in beans.

Biosynthesis and Characterization of Zinc Oxide Nanoparticles (ZnO-NPs) Utilizing Banana Peel Extract

Biosynthesis and Characterization of Zinc Oxide Nanoparticles (ZnO-NPs) Utilizing Banana Peel Extract

Sunlight and microwave catalyzed comparative biosynthesis of silver nanoparticles using in-vitro and in-vivo biomass of Fagonia schweinfurthii Hadidi, its antibacterial activity and phytotoxicity

In the present study, we explore the potential of Fagonia schweinfurthii Hadidi (FS) in-vivo plant material and in-vitro-grown callus as a bio-template for AgNPs synthesis, highlighting its eco-friendly and bio-inspired sustainable approach. The comparative efficacy of natural plant material and its callus culture was assessed for AgNP synthesis by employing both sunlight and microwave irradiation as separate synthesis methods. This yielded four distinct types of AgNPs denoted as CS-AgNPs, PS-AgNPs, CM-AgNPs, and PM-AgNPs. Sunlight-irradiated AgNP synthesis optimized at near to neutral pH (6.6), whereas microwave-assisted synthesis needed a basic pH for synthesis. Optimization of these AgNPs involved varying concentrations of AgNO3, plant aqueous extract (PAE), and callus aqueous extract (CAE) of FS, exposure time to sunlight and microwave radiation, as well as pH adjustments. The particle size of these AgNPs ranged from 5 to 30 nm, having a crystalline nature with a similar fringe width of 0.22 nm, as observed from HR-TEM analysis. These AgNPs showed significant antibacterial properties against the clinical isolates with λmax 420 nm. Importantly, CAE outperformed PAE for the biosynthesis of AgNPs, mainly in the presence of sunlight-producing CS-AgNPs. These CS-AgNPs are rapidly synthesized, well dispersed and stable, showing significant antibacterial activity, and the least environmental phytotoxicity. It promoted the number of secondary roots, seedling DW, and TWC with 100% seed germination. This highlights their sustainable features for exploring industrial eco-friendly nonmanufacturing of AgNPs using callus culture and sunlight irradiation.

Biosynthesis of Ag-Doped CuO Nanoparticles Using Heracleum persicum Extract for Enhanced Antibacterial and Photocatalytic Dye Degradation Properties

Biosynthesis of Ag-Doped CuO Nanoparticles Using Heracleum persicum Extract for Enhanced Antibacterial and Photocatalytic Dye Degradation Properties

Biosynthesis and antibacterial activity of ZnO nanoparticles using Buchanania obovata fruit extract and the eutectic-based ionic liquid

The fruit extract of Buchanania obovata and the eutectic-based ionic liquid were utilized, in an eco-friendly, inexpensive, simple method, for synthesizing zinc oxide nanoparticles (ZnO NPs). The influence of the reducing, capping and stabilizing agents, in both mediums, on the structure, optical, and morphological properties of ZnO NPs was extensively investigated. The surface plasmon resonance peaks were observed at 340 nm and 320 nm for the fruit-based and the eutectic-based ionic liquid mediums, respectively, indicating the formation of ZnO NPs. XRD results confirmed the wurtzite structure of the ZnO NPs, exhibiting hexagonal phases in the diffraction patterns. The SEM and TEM images display that the biosynthesized ZnO NPs exhibit crystalline and hexagonal shape, with an average size of 40 nm for the fruit-based and 25 nm for the eutectic-based ionic liquid. The Brunauer–Emmett–Teller (BET) surface area analysis, revealed a value ∼13 m2 g−1 for ZnO NPs synthesized using the fruit extract and ∼29 m2 g−1 for those synthesized using the eutectic-based ionic liquid. The antibacterial activity of the biosynthesized ZnO NPs was assessed against clinically isolated Gram-negative (E. coli) and Gram-positive (S. aureus) bacterial strains using the inhibition zone method. The ZnO NPs produced from the eutectic-based ionic liquids confirmed superior antibacterial activity against both S. aureus and E. coli compared to those mediated by the utilized fruit extract. At a concentration of 1000, the eutectic-based ionic liquid mediated ZnO NPs displayed a maximum inhibition zone of 16 mm against S. aureus, while against E. coli, a maximum inhibition zone of 15 mm was observed using the fruit extract mediated ZnO NPs. The results of this study showed that the biosynthesized ZnO NPs can be utilized as an efficient substitute to the frequently used chemical drugs and covering drug resistance matters resulted from continual usage of chemical drugs by users.

Synthesis of bio-stabilized silver nanoparticles using Roccella montagnei, their anticandidal capacities & potential to inhibit the virulence factors in fluconazole-resistant Candida albicans.

Candida species is the causative agent in approximately 80% of invasive mycoses and drug-resistant Candida albicans is among the four strains of 'critical priority group' framed by WHO. Lichens are endowed with some rare phytochemicals and a plethora of therapeutics viz. antifungal capacities of Roccella montagnei. Biosynthesis of silver nanoparticles (AgNPs) using lichen could offer an eco-friendly, and cost-effective alternative against emerging 'microbial resistance.' Therefore, the objective was to biosynthesize silver nanoparticles (Rm-AgNPs) using a Hydro-alcoholic (1:1) extract of R. montagnei to develop a potent anticandidal agent against Fluconazole-resistant C. albicans NBC099. UV-Spectroscopy identified AgNPs specific-peak of Rm-AgNPs at 420-440nm and FTIR revealed the presence of amines, alcohol, aromatic compounds, and acids. SEM and TEM analysis indicated that Rm-AgNPs are spherical shaped with a size range of 10-50nm. Zetasizer analysis indicated that particles are highly stable and have a mean hydrodynamic diameter of 116nm with a zeta potential charge of - 41mV. XRD analysis suggested face centered cubic crystal lattice structure. Results indicated that Rm-AgNPs strongly inhibited the growth of NBC099 at a minimum inhibitory concentration (IC50) of ≤ 15µg. C. albicans culture treated with Rm-AgNPs at concentrations below IC50, down-regulates the production of different virulence factors in NBC099, viz. hyphal formation (> 85%), biofilms production (> 80%), phospholipase, esterase, proteinase activity. The apoptosis assay demonstrated the Rm-AgNPs induced apoptosis in NBC099 cells via oxidative stress. Interestingly, Rm-AgNPs showed negligible cytotoxicity (< 6%) in murine RAW 246.7 macrophage cells at a concentration above 15µg/mL. Therefore, Rm-AgNPs have been offered as an anti-candida alternative that can be utilized to improve the efficacy of already available medications.

Biosynthesis of Copper Nanoparticles from Acacia cornigera and Annona purpurea and Their Insecticidal Effect against Tribolium castaneum

Diverse studies have showed that the pesticides can cause important damages in ecosystem. Therefore, the development of bio pesticides through nanotechnology can increase efficacy and limit the negative impacts in the environmental that traditionally seen through the use of chemical pesticides. Nanoparticles obtained from plants’ extracts can be used for effective pest management as a combined formulation of metal and some other organic material present in the plants. In the present study, our evaluated biosynthesis of nanoparticles of copper used two plant extracts (Acacia cornigera and Annona purpurea), and the Taguchi method was adopted for the synthesis optimization of the following variables of biosynthesis: temperature, pH, extract concentration, and reaction times to maximize the insecticidal activity on Tribolium castaneum. Our results showed that the nanoparticles were successfully synthesized using Acacia cornigera and Anona purpurea extract under optimum conditions under Taguchi L 9 orthogonal design, where copper nanoparticles were obtained with a size of 63–153 nm for using A. cornigera extract, 87–193 nm for A. purpurea extract, and a zeta potential of 9.6 mV and −32.7 mV, respectively. The nanoparticles of copper from A. cornigera showed effective insecticidal activity against Tribolium castaneum, and 90% mortality compared to the 76.6% obtained from nanoparticles of copper from A. purpurea. The results suggest that Cu-nanoparticles derived from both plants could be used as a biocontrol agent of Tribolium castaneum, a pest of stored grain with great economic importance.

Use of Residual Malt from an Artisanal Beer Brewing Process in the Biosynthesis of Silver Nanoparticles Mediated by Nucleating and Structure-Directing Agents.

Biosynthesized silver nanoparticles (AgNPs) are widely used in varied applications, which are morphology dependent. Consequently, a morphology-controlled synthesis is mandatory. Although there are several studies focused on the plant extract-based biosynthesis of metallic nanoparticles, the use of extracts obtained from agro-wastes is scant. Furthermore, information regarding morphology modification through the use of additional agents is even more scarce. Thus, in this study, AgNPs were synthesized using a malt extract (ME) obtained from an artisanal beer brewing process residue. Additionally, sodium chloride (NaCl), gum arabic (GA), and talc (T) were used in an attempt to modify the morphology of AgNPs. XRD, DLS, SEM, and TEM results demonstrate that stable AgNPs of different sizes and shapes were synthesized. FTIR, HPLC analysis, and the quantification of total proteins, free amino acids, reducing sugars, and total polyphenols before and after AgNPs synthesis showed that ME biomolecules allowed them to act as a source of reducing and stabilizing agents. Therefore, this study provides evidence that ME can be successfully used to biosynthesize AgNPs. Additionally, the antibacterial activity of AgNPs against Gram-negative and Gram-positive bacteria was evaluated. Results indicate that AgNPs show a higher antibacterial activity against Gram-positive bacteria.

Green Biosynthesis and characterization of organic Fructus mori-composite silver nanoparticles: Enhanced antioxidant and antibacterial activities

The bacterial resistance to antibiotics is becoming a major challenge worldwide. The novel antimicrobial silver nanomaterial without bacterial resistance has the hope of becoming a suitable substitute for antibiotics. However, it is necessary to produce nanosilver with appropriate size and better antimicrobial performance through a green and simple synthesis process. In the present study, Fructus mori-composite silver nanoparticles (M-AgNPs) were greenly biosynthesized using mulberry fruits (Fructus mori). Ultraviolet-visible (UV-vis) spectroscopy and X-ray diffraction (XRD) indicated the formation of M-AgNPs with face centered cubic structure. Fourier transform infrared (FTIR) spectroscopy confirmed reducing and capping effects of mulberry fruits' organic matter (polyphenols, flavonoids, etc.) on M-AgNPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed that M-AgNPs were spherical and equably distributed, with a size of about 28 nm and an excellent stability. The antioxidant activity of M-AgNPs was evaluated by 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) assay, and the highest DPPH clearance rate was 84.69±3.68 %. M-AgNPs wrapped by biomolecules exhibited stronger antibacterial activity than chemically synthesized commercial nanosilver. M-AgNPs' diameters of inhibition zone against P. aeruginosa, E. coli and S. aureus were 13.9 ± 0.4, 12.2 ± 0.3 and 12.8 ± 0.7 mm, respectively. The minimal inhibitory concentrations of M-AgNPs against E. coli and S. aureus were 4 μg/mL and 16 μg/mL, respectively, and the minimal bactericidal concentrations were 4 μg/mL and 32 μg/mL, respectively. M-AgNPs showed time-dependent damage to the cell morphology of pathogens. Such biosynthesized organic silver nanoparticles have good prospects for biomedical applications.